Putin’s decision to respond to the ouster of a pro-Moscow government in Ukraine by deploying troops across Crimea and threatening to send them into eastern Ukraine has inflamed already painful relations with the United States. Some (wrongly) see the birth of a new Cold War. And some wonder whether the judo-loving former KGB colonel with the nuclear arsenal and the unsettling fondness for being photographed shirtless might be insane.

He isn’t – at least not according to senior Obama aides, career military and intelligence officials, and Rep. Adam Schiff, a top Democratic member of the House Intelligence Committee.

That doesn’t sound like someone looking to put relations with the West back in the deep freeze of the Cold War, a unique clash of ideologies that ranged all over the world. But Putin hasn’t been shy about declaring that he wants to restore Russia’s badly eroded great-power status, calling for a “Eurasian Union” with the land of the tsars at its heart.

“When it comes to Ukraine, we certainly understand how important it is to his vision of a greater Russia – it really doesn’t work without Ukraine,” said Schiff.

But “some people keep describing him as a master chess player. That gives him way too much credit. He’s not so much a chess-player as he is a bully,” the lawmaker said.

Is Putin “unhinged,” a reporter asked a senior administration official at a briefing late Tuesday? No, but he has a deep-seated sense of grievance against the United States, replied the official, who under the ground rules for the question-and-answer session could neither be identified nor quoted directly.

Maybe more important, the official continued, is that Putin saw widespread demonstrations at home against his reelection as president, watched the “Arab Spring” protests spread across the region, and worried that what happened in Kiev might set off unrest in Moscow.

What about the risk that sanctions against Russia might trigger an angry retaliation from Putin, whether by sabotaging nuclear talks with Iran, or closing air routes that are expected to be crucial to the U.S. withdrawal from Afghanistan, or helping Syria's Bashar Assad escape international pressure to destroy his chemical weapons?

The official said Putin worries about a nuclear-armed Iran, wants the United States out of Afghanistan, and has invested considerable personal prestige in making the deal with Syria work. He didn’t say it explicitly, but those factors all suppose that Putin is calculating, not insane, or, as a retired career intelligence official who has dealt with top aides to Putin told Yahoo News, “Another way you could say it is that he’s ‘miscalculating,’ not crazy. He does get things wrong.”

And he’s worried.

“One thing that led to this response was the deep suspicion that Putin harbors about these protests that toppled the pro-Moscow government in Ukraine,” explained Professor Michael Kraus, who heads Russian and East European studies at Middlebury College. “He sees a Western hand in that, and also he fears that kind of movement in Russia itself.”

Putin also thinks the West judges his actions more harshly than its own. NATO waged an air war in 1999 against Russian ally Serbia as part of an ultimately successful effort to give what was then that country’s Kosovo region independence.

“That played huge in Russia,” said Kraus. Putin thinks that “if the West could declare Kosovo an independent state, then it clearly paves the way for Russia to do the same.”

Putin’s insistence that there is a double-standard shines through in one confrontation Bush recounts in his presidential memoir “Decision Points.”

At a 2007 joint press conference with Putin, Bush was asked whether he regretted saying six years earlier that he looked into Putin’s eyes, got “a sense of his soul,” and declared him worthy of trust.

“Here's the thing when you're dealing with a world leader, you wonder whether or not he's telling the truth or not. I've never had to worry about that with Vladimir Putin,” Bush replied. “Sometimes he says things I don't want to hear, but I know he's always telling me the truth. And you don't have to guess about his opinions, which makes it a lot easier to find common ground.”

It wasn’t that long ago that Obama, too, was putting the best face on frequently tense relations with Putin.

“It was a candid and constructive conversation, which characterizes my relationship with him,” Obama said after talks at the G20 summit in St Petersburg, Russia. “Everybody is always trying to look for body language and all that. But the truth of the matter is that my interactions with him tend to be very straightforward.”

But reaching Putin isn’t an easy job. His spymaster’s sense that everything might be a trap came through clearly at a June 2013 joint press conference in an exchange that Obama meant as a bit of self-deprecating small talk.

“We compared notes on President Putin’s expertise in judo and my declining skills in basketball,” Obama said with a broad grin, getting laughter from the crowd and a tense-looking smile from Putin. “And we both agreed that as you get older it takes more time to recover.”

But one of the most telling exchanges belonged to Bush – and it was the last time the two leaders spoke, apart from a cursory goodbye call when the Republican left the White House.

Bush was unhappy with Russia’s actions in Georgia. Upon spotting Putin in the heads-of-state box at the Olympics in Beijing, Bush approached him and scolded him, saying Georgia’s leader, Mikheil Saakashvili, was “hot-blooded.”

“I’m hot-blooded too,” Putin replied.

“I stared back at him,” Bush writes in his book. “‘No Vladimir,’ I said. ‘You’re cold-blooded.’”